Windows 7 Build 7601

Installed Windows 7 Pro and activated using MTK 2.6.2
Working Fine and then I decided to purchase a CD Key. I added the new CD Key and was good for a few months and then I get a pop up one morning this copy is not genuine, the bottom right corner shows Build 7601

I tried using MTK 2.6.2 again, and EZ Activator is successful, but even after restarting multiple times I still have the same pop up and Build 7601 message in the corner.

Installed Windows 7 Pro and activated using MTK 2.6.2
Working Fine and then I decided to purchase a CD Key. I added the new CD Key and was good for a few months and then I get a pop up one morning this copy is not genuine, the bottom right corner shows Build 7601

I tried using MTK 2.6.2 again, and EZ Activator is successful, but even after restarting multiple times I still have the same pop up and Build 7601 message in the corner.